Supported by grants from the Department of Defense (W81XWH-09-1-0127), the NIH (2-R01-CA089569), the Elsa U. Pardee Foundation, a Marsha Rivkin Center for Ovarian Cancer Research Pilot Study Award, and generous philanthropic support from Section of Urology and Section of Research in the Department of Surgery, University of Chicago.

All mice were housed, maintained and euthanized according to Institutional Animal Care and Use Committee (IACUC) guidelines and under the supervision of the University of Chicago Animal Resource Center.
1. Preparing Animals for Experimental Studies
<ol>
	<li>Allow animals to acclimate to new housing and environment, to recover from potential physiologic effects of transport and handling. 
	Note: The following technique is applicable to all commercially available strains of mice. The num...

<ol>
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Development of therapies to target disseminated cells requires a mechanistic understanding of metastatic colonization, the critical first step in the development of peritoneal disease. To address these issues we report approaches that can be used to discern how the omentum&#8217;s unique tissue composition and architecture promote ovarian cancer metastatic colonization. Distinguishing features of our approach are: 1) the focus on early events in the colonization process; 2) comparison of milky spot-containing an...

Unlike most solid tumors, metastases from high-grade serous ovarian cancer (HGSC) are limited to the peritoneal cavity 1. Thus, effective peritoneal therapies could potentially control or eradicate HGSC. Currently, a standard therapeutic approach is surgical cytoreduction combined with chemotherapy 1-3. Unfortunately, the vast majority of patients experience and succumb to complications of disease recurrence. These dismal statistics show the need for improved understanding of metastatic colonization, the process by which cancer cells localize to, utilize, and proliferate within host tissues to form metastases 2.
The omentum is a preferred early site of HGSC metastasis 4-7. Unlike other peritoneal adipose, omental adipose tissue contains unusual immune structures known as milky spots, which contain B, T, and NK cells and macrophages, which play key roles in peritoneal homeostasis8,9. In addition to their physiologic functions, we found that milky spots play an active role in ovarian cancer metastatic colonization 4. In experimental metastasis assays, SKOV3ip.1, CaOV3, and HeyA8 (human) and ID8 (murine; C57BL/6) ovarian cancer cells rapidly home to milky spots, suggesting that the cells are moving toward a secreted chemotactic factor. Interestingly, cancer cells do not colonize peritoneal adipose lacking milky spots (i.e., gonadal and uterine fat) 4.
In order to identify mechanisms regulating milky spot colonization, we have optimized xenograft models that enable the interrogation of cellular and molecular events over the time course of metastatic colonization 4. A specific advantage of the approaches described herein is its emphasis on tissue architecture and function, which enables users to test hypotheses in fully integrated in vivo and ex vivo models of metastatic colonization 4,10. By comparing cancer cell localization and growth in peritoneal fat depots which either contain or lack milky spots, investigators can test the relative contribution(s) of adipocytes and cells within milky spots to the lodging and progressive growth of ovarian cancer cells in physiologically relevant tissues.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Dissection Tools</td>
			<td>Fine Science Tools</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr>
			<td>Geimsa</td>
			<td>Fluka/Sigma Aldrich</td>
			<td>48900</td>
			<td></td>
		</tr>
		<tr>
			<td>5% Formalin</td>
			<td>Sigma</td>
			<td>HT501320</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>Corning</td>
			<td>10-013-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin</td>
			<td>Gibco</td>
			<td>25200-056</td>
			<td></td>
		</tr>
		<tr>
			<td>PBS</td>
			<td>Corning</td>
			<td>21-040-CV</td>
			<td>Without calcium and Magnesium</td>
		</tr>
		<tr>
			<td>26 gauge needle</td>
			<td>BD</td>
			<td>329652</td>
			<td></td>
		</tr>
		<tr>
			<td>BSA</td>
			<td>Sigma</td>
			<td>A7906</td>
			<td></td>
		</tr>
		<tr>
			<td>Collagenase</td>
			<td>Worthington</td>
			<td>LS004196</td>
			<td></td>
		</tr>
		<tr>
			<td>Stomacher</td>
			<td>Seward Labsystems</td>
			<td>Stomacher 80 Biomaster</td>
			<td></td>
		</tr>
		<tr>
			<td>Microstomacher bag</td>
			<td>Stomacher Lab Systems</td>
			<td>BA6040/Micro</td>
			<td></td>
		</tr>
		<tr>
			<td>ACK Lysis Buffer</td>
			<td>Gibco</td>
			<td>A10492-01</td>
			<td></td>
		</tr>
		<tr>
			<td>Millicell culture plate insert</td>
			<td>Millipore</td>
			<td>PICM01250</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell-Tak</td>
			<td>BD</td>
			<td>354240</td>
			<td></td>
		</tr>
	</tbody>
</table>

in vivo and ex vivo approaches to study ovarian cancer metastatic colonization of milky spot structures in peritoneal adipose

High-grade serous ovarian cancer (HGSC), the cause of widespread peritoneal metastases, continues to have an extremely poor prognosis; fewer than 30% of women are alive 5 years after diagnosis. The omentum is a preferred site of HGSC metastasis formation. Despite the clinical importance of this microenvironment, the contribution of omental adipose tissue to ovarian cancer progression remains understudied. Omental adipose is unusual in that it contains structures known as milky spots, which are comprised of B, T, and NK cells, macrophages, and progenitor cells surrounding dense nests of vasculature. Milky spots play a key role in the physiologic functions of the omentum, which are required for peritoneal homeostasis. We have shown that milky spots also promote ovarian cancer metastatic colonization of peritoneal adipose, a key step in the development of peritoneal metastases. Here we describe the approaches we developed to evaluate and quantify milky spots in peritoneal adipose and study their functional contribution to ovarian cancer cell metastatic colonization of omental tissues both in vivo and ex vivo. These approaches are generalizable to additional mouse models and cell lines, thus enabling the study of ovarian cancer metastasis formation from initial localization of cells to milky spot structures to the development of widespread peritoneal metastases.

Identification and Histologic Examination of Peritoneal Fat Depots
Gross anatomic dissection allows identification of four of the five primary sources of peritoneal fat (Figure 1A). Moving clockwise from the top center are: the omentum (OM; outlined) located over the stomach and spleen, the gonadal fat (GF) surrounding the left ovary (ov), the uterine fat (UF) attached to the uterine horns (uh) and the mesentery (MY) attached to the small intestine (si). The o...

Watch this Scientific Journal Video about In Vivo and Ex Vivo Approaches to Study Ovarian Cancer Metastatic Colonization of Milky Spot Structures in Peritoneal Adipose at JoVE.com

In Vivo and Ex Vivo Approaches to Study Ovarian Cancer Metastatic Colonization of Milky Spot Structures in Peritoneal Adipose

We outline a protocol that implements both in vivo and ex vivo approaches to study ovarian cancer colonization of peritoneal adipose tissues, particularly the omentum. Furthermore, we present a protocol to quantitate and analyze immune cell-structures in the omentum known as milky spots, which promote metastases of peritoneal adipose.

In Vivo and Ex Vivo Approaches to Study Ovarian Cancer Metastatic Colonization of Milky Spot Structures in Peritoneal Adipose

High-grade serous ovarian cancer (HGSC), the cause of widespread peritoneal metastases, continues to have an extremely poor prognosis; fewer than 30% of ...

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12.9K visualizações.  The University of Chicago. We outline a protocol that implements both in vivo and ex vivo approaches to study ovarian cancer colonization of peritoneal adipose tissues, particularly the omentum. Furthermore, we present a protocol to quantitate and analyze immune cell-structures in the omentum known as milky spots, which promote metastases of peritoneal adipose.